Green’s Dictionary of Slang

rushn.

1. in senses of lit. or fig. overwhelming.

(a)
[late 18C–early 19C] (UK Und.) robbery with violence; if the rush, then usu. of a single item, e.g. a cloak hanging outside a shop; if a rush, an assault by a number of men on a house with the intent of robbing the owners of their money and valuables.